Mir – Wikipedia, the free encyclopedia

Mir Mir on 9 February 1998 as seen from the departing Space ShuttleEndeavour during STS-89 Mir insignia Station statistics COSPAR ID 1986-017A Call sign Mir Crew 3 Launch 20 February 1986 23 April 1996 Launch pad LC-200/39, and LC-81/23, Baikonur Cosmodrome LC-39A, Kennedy Space Center Reentry 23 March 2001 05:59 UTC Mass 129,700 kg (285,940 lbs) Length 19m (62.3ft) from the core module to Kvant-1 Width 31m (101.7ft) from Priroda to the docking module Height 27.5m (90.2ft) from Kvant-2 to Spektr Pressurised volume 350 m Atmospheric pressure c.101.3kPa (29.91inHg, 1 atm) Perigee 354km (189nmi) AMSL Apogee 374km (216nmi) AMSL Orbital inclination 51.6 degrees Average speed 7,700m/s (27,700km/h, 17,200mph) Orbital period 91.9 minutes Orbits per day 15.7 Days in orbit 5,519 days Days occupied 4,592 days Number of orbits 86,331 Statistics as of 23 March 2001 (unless noted otherwise) References: [1][2][3][4][5][6][7][8][9][10][11][12] Configuration Station elements as of May 1996.

Mir (Russian: , IPA:[mir]; lit.Peace or World) was a space station that operated in low Earth orbit from 1986 to 2001, owned by the Soviet Union and later by Russia. Mir was the first modular space station and was assembled in orbit from 1986to1996. It had a greater mass than that of any previous spacecraft. Until 21 March 2001 it was the largest satellite in orbit, succeeded by the International Space Station after Mir's orbit decayed. The station served as a microgravity research laboratory in which crews conducted experiments in biology, human biology, physics, astronomy, meteorology and spacecraft systems with a goal of developing technologies required for permanent occupation of space.

Mir was the first continuously inhabited long-term research station in orbit and set the record for the longest continuous human presence in space at 3,644 days until 23 October 2010 when it was surpassed by the ISS.[13] It holds the record for the longest single human spaceflight, with Valeri Polyakov spending 437 days and 18 hours on the station between 1994 and 1995. Mir was occupied for a total of twelve and a half years out of its fifteen-year lifespan, having the capacity to support a resident crew of three, or larger crews for short term visits.

Following the success of the Salyut programme, Mir represented the next stage in the Soviet Union's space station programme. The first module of the station, known as the core module or base block, was launched in 1986, and followed by six further modules. Proton rockets were used to launch all of its components except for the docking module, which was installed by space shuttle mission STS-74 in 1995. When complete, the station consisted of seven pressurised modules and several unpressurised components. Power was provided by several photovoltaic arrays attached directly to the modules. The station was maintained at an orbit between 296km (184mi) and 421km (262mi) altitude and traveled at an average speed of 27,700km/h (17,200mph), completing 15.7 orbits per day.[6][7][8]

The station was launched as part of the Soviet Union's manned spaceflight programme effort to maintain a long-term research outpost in space, and, following the collapse of the USSR, was operated by the new Russian Federal Space Agency (RKA). As a result, the vast majority of the station's crew were Russian; however, through international collaborations such as the Intercosmos, Euromir and Shuttle-Mir programmes, the station was made accessible to astronauts from North America, several European nations and Japan. Mir was deorbited in March 2001 because of a lack of funding. The cost of the Mir programme was estimated by former RKA General Director Yuri Koptev in 2001 as $4.2 billion over its lifetime (including development, assembly and orbital operation).[14]

Mir was authorised in a decree made on 17 February 1976 to design an improved model of the Salyut DOS-17K space stations. Four Salyut space stations had already been launched since 1971, with three more being launched during Mir's development. It was planned that the station's core module (DOS-7 and the backup DOS-8) would be equipped with a total of four docking ports; two at either end of the station as with the Salyut stations, and an additional two ports on either side of a docking sphere at the front of the station to enable further modules to expand the station's capabilities. By August 1978, this had evolved to the final configuration of one aft port and five ports in a spherical compartment at the forward end of the station.[15]

It was originally planned that the ports would connect to 7.5 tonne modules derived from the Soyuz spacecraft. These modules would have used a Soyuz propulsion module, as in Soyuz and Progress, and the descent and orbital modules would have been replaced with a long laboratory module.[15] However, following a February 1979 governmental resolution, the programme was consolidated with Vladimir Chelomei's manned Almaz military space station programme. The docking ports were reinforced to accommodate 20tonne (22short tons) space station modules based on the TKS spacecraft. NPO Energia was responsible for the overall space station, with work subcontracted to KB Salyut, due to ongoing work on the Energia rocket and Salyut 7, Soyuz-T, and Progress spacecraft. KB Salyut began work in 1979, and drawings were released in 1982 and 1983. New systems incorporated into the station included the Salyut 5B digital flight control computer and gyrodyne flywheels (taken from Almaz), Kurs automatic rendezvous system, Luch satellite communications system, Elektron oxygen generators, and Vozdukh carbon dioxide scrubbers.[15]

By early 1984, work on Mir had ground to a halt while all resources were being put into the Buran programme in order to prepare the Buran spacecraft for flight testing. Funding resumed in early 1984 when Valentin Glushko was ordered by the Central Committee's Secretary for Space and Defence to orbit Mir by early 1986, in time for the 27th Communist Party Congress.[15]

It was clear that the planned processing flow could not be followed and still meet the 1986 launch date. It was decided on Cosmonaut's Day (12 April) 1985 to ship the flight model of the base block to the Baikonur cosmodrome and conduct the systems testing and integration there. The module arrived at the launch site on 6 May, with 1100 of 2500 cables requiring rework based on the results of tests to the ground test model at Khrunichev. In October, the base block was rolled outside its cleanroom to carry out communications tests. The first launch attempt on 16 February 1986 was scrubbed when the spacecraft communications failed, but the second launch attempt, on 19 February 1986 at 21:28:23 UTC, was successful, meeting the political deadline.[15]

The orbital assembly of Mir began in February 1986 with the launch of the core module on a Proton-K rocket. Four of the six modules which were later added (Kvant-2 in 1989, Kristall in 1990, Spektr in 1995 and Priroda in 1996) followed the same sequence to add themselves to the main Mir complex. Firstly, the module would be launched independently on its own Proton-K and chase the station automatically. It would then dock to the forward docking port on the core module's docking node, then extend its Lyappa arm to mate with a fixture on the node's exterior. The arm would then lift the module away from the forward docking port and rotate it on to the radial port that the module was to mate with, before lowering it down to dock. The node was equipped with only two Konus drogues, however, which were required for dockings. This meant that, prior to the arrival of each new module, the node would have to be depressurised to allow spacewalking cosmonauts to manually relocate the drogue to the next port to be occupied.[6][17]

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Mir - Wikipedia, the free encyclopedia